Pippa Middleton in her bridesmaid dress, designed by Sarah Burton for Alexander McQueen; and the almost identical version currently on sale at Net-a-porter.com. Photo: Reuters

Cameron Diaz at the 2010 Golden Globes in an Alexander McQueen design similar to Pippa Middleton's bridesmaid dress. Photo: Rex

The cowl-neck dress, designed by Sarah Burton for Alexander McQueen, has only minor differences to the original gown, with a covered zip at the back in place of Pippa's fabric buttons and an alternative finish to the sleeve and neck seams.

Adored by the public and press alike, the simplistic design quickly thrust Pippa into the limelight, making her the surprise fashion hit of the royal wedding day and garnering attention for her elegance and shapely figure. But it isn't the only time Sarah Burton has used the classic design. Actress Cameron Diaz wore a red satin version from the pre-fall 2009 collection for the 2010 Golden Globes and the popular shape continues to sell quickly this season, with navy and red knee-length versions currently out of stock on Net-a-porter as well.

Unsurprisingly, those keen to get their hands on the pure silk gown will have to move quickly as the smallest size has already sold out. But the price tag might be a consolation - although not a snip at £1,995 - it is considerably less than the £20,000 the Middletons are rumoured to have paid for the original.